Migrate build system to Kotlin DSL, centralize versions, and modernize source files

README.md

@@ -7,22 +7,18 @@ For an explanation of the layout of this repository, see
 
 ## Build and run
 
-[![build](https://github.com/android/ndk-samples/actions/workflows/build.yml/badge.svg)](https://github.com/android/ndk-samples/actions)
-
-1. Clone the repository
-2. Open the whole project in Android Studio
-3. Install CMake 4.1.0 via the SDK Manager (must be done manually until
-   https://issuetracker.google.com/443137057 is fixed).
-4. Select the sample you want to run in the top bar (you may need to sync gradle
-   first)
-5. Click the play button to run the sample
-
-You can also build the samples from the command line if you prefer. Use
-`./gradlew build` to build everything (if you're on Windows, use `.\gradlew.bat`
-instead of `./gradlew`). For individual tasks, see `./gradlew tasks`. To see the
-tasks for an individual sample, run the `tasks` task for that directory. For
-example, `./gradlew :camera:basic:tasks` will show the tasks for the
-`camera/basic` app.
+1. Clone the repository.
+2. Open the project in Android Studio (Ladybug or newer recommended).
+3. The project will automatically configure the required **NDK** and **CMake** versions
+   defined in the [Version Catalog](gradle/libs.versions.toml).
+4. Select the sample you want to run in the top bar.
+5. Click the play button to run the sample.
+
+You can also build the samples from the command line using the Gradle wrapper:
+- macOS/Linux: `./gradlew build`
+- Windows: `.\gradlew.bat build`
+
+To build specific module/app you can use a command like: `./gradlew :camera:basic:tasks`
 
 ## I just want something to copy from as a starting point
 

base/src/main/cpp/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.22.1)
+cmake_minimum_required(VERSION 4.1.0)
 project(Base LANGUAGES CXX)
 
 include(AppLibrary)

base/src/main/cpp/logging_splitters.h

@@ -16,8 +16,8 @@
 
 #pragma once
 
-#include <inttypes.h>
-#include <time.h>
+#include <cinttypes>
+#include <ctime>
 
 #include <format>
 

bitmap-plasma/app/build.gradle.kts

@@ -0,0 +1,23 @@
+plugins {
+    id("ndksamples.android.application")
+}
+
+android {
+    namespace = "com.example.plasma"
+    defaultConfig {
+        applicationId = "com.example.plasma"
+    }
+    externalNativeBuild {
+        cmake {
+            path = file("src/main/cpp/CMakeLists.txt")
+        }
+    }
+
+    buildFeatures {
+        prefab = true
+    }
+}
+
+dependencies {
+    implementation(project(":base"))
+}

bitmap-plasma/app/src/main/cpp/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.22.1)
+cmake_minimum_required(VERSION 4.1.0)
 project(BitmapPlasma LANGUAGES CXX)
 
 include(AppLibrary)

bitmap-plasma/app/src/main/cpp/plasma.cpp

@@ -17,10 +17,10 @@
 #include <android/bitmap.h>
 #include <android/log.h>
 #include <jni.h>
-#include <math.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <time.h>
+#include <cmath>
+#include <cstdio>
+#include <cstdlib>
+#include <ctime>
 
 #define LOG_TAG "libplasma"
 #define LOGI(...) __android_log_print(ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__)

bitmap-plasma/app/src/main/java/com/example/plasma/Plasma.java

@@ -17,14 +17,13 @@
 
 import android.annotation.SuppressLint;
 import android.app.Activity;
-import android.graphics.Point;
-import android.os.Bundle;
 import android.content.Context;
-import android.view.View;
 import android.graphics.Bitmap;
 import android.graphics.Canvas;
+import android.graphics.Point;
+import android.os.Bundle;
 import android.view.Display;
-import android.view.WindowManager;
+import android.view.View;
 
 public class Plasma extends Activity
 {

build-logic/build.gradle.kts

@@ -1,3 +1,4 @@
+import org.jetbrains.kotlin.gradle.dsl.JvmTarget
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 
 plugins {
@@ -12,8 +13,8 @@ java {
 }
 
 tasks.withType<KotlinCompile>().configureEach {
-    kotlinOptions {
-        jvmTarget = JavaVersion.VERSION_17.toString()
+    compilerOptions {
+        jvmTarget.set(JvmTarget.JVM_17)
     }
 }
 

build-logic/src/main/java/com/android/ndk/samples/buildlogic/AndroidApplicationConventionPlugin.kt

@@ -1,31 +1,42 @@
 package com.android.ndk.samples.buildlogic
 
 import com.android.build.api.dsl.ApplicationExtension
+import org.gradle.api.JavaVersion
 
 import org.gradle.api.Plugin
 import org.gradle.api.Project
+import org.gradle.api.artifacts.VersionCatalogsExtension
 import org.gradle.kotlin.dsl.configure
+import org.gradle.kotlin.dsl.getByType
 
 class AndroidApplicationConventionPlugin : Plugin<Project> {
     override fun apply(target: Project) {
+        val libs = target.extensions.getByType<VersionCatalogsExtension>().named("libs")
+        val compileSdkVersion = libs.findVersion("compileSdk").get().requiredVersion.toInt()
+        val minSdkVersion = libs.findVersion("minSdk").get().requiredVersion.toInt()
+        val targetSdkVersion = libs.findVersion("targetSdk").get().requiredVersion.toInt()
+        val ndkVersionStr = libs.findVersion("ndk").get().requiredVersion
+        val cmakeVersionStr = libs.findVersion("cmake").get().requiredVersion
+        val javaVersion = JavaVersion.toVersion(libs.findVersion("javaTarget").get().requiredVersion)
+
         with(target) {
             with(pluginManager) {
                 apply("com.android.application")
             }
 
             extensions.configure<ApplicationExtension> {
-                compileSdk = Versions.COMPILE_SDK
-                ndkVersion = Versions.NDK
+                compileSdk = compileSdkVersion
+                ndkVersion = ndkVersionStr
 
                 externalNativeBuild {
                     cmake {
-                        version = Versions.CMAKE
+                        version = cmakeVersionStr
                     }
                 }
 
                 defaultConfig {
-                    minSdk = Versions.MIN_SDK
-                    targetSdk = Versions.TARGET_SDK
+                    minSdk = minSdkVersion
+                    targetSdk = targetSdkVersion
 
                     externalNativeBuild {
                         cmake {
@@ -51,8 +62,8 @@ class AndroidApplicationConventionPlugin : Plugin<Project> {
                     }
                 }
                 compileOptions {
-                    sourceCompatibility = Versions.JAVA
-                    targetCompatibility = Versions.JAVA
+                    sourceCompatibility = javaVersion
+                    targetCompatibility = javaVersion
                 }
 
                 // Studio will not automatically pass logcat through ndk-stack, so we need to avoid

build-logic/src/main/java/com/android/ndk/samples/buildlogic/AndroidLibraryConventionPlugin.kt

@@ -1,34 +1,45 @@
 package com.android.ndk.samples.buildlogic
 
 import com.android.build.api.dsl.LibraryExtension
+import org.gradle.api.JavaVersion
 import org.gradle.api.Plugin
 import org.gradle.api.Project
+import org.gradle.api.artifacts.VersionCatalogsExtension
 import org.gradle.kotlin.dsl.configure
+import org.gradle.kotlin.dsl.getByType
 
 class AndroidLibraryConventionPlugin : Plugin<Project> {
     override fun apply(target: Project) {
+        val libs = target.extensions.getByType<VersionCatalogsExtension>().named("libs")
+        val compileSdkVersion = libs.findVersion("compileSdk").get().requiredVersion.toInt()
+        val minSdkVersion = libs.findVersion("minSdk").get().requiredVersion.toInt()
+        val targetSdkVersion = libs.findVersion("targetSdk").get().requiredVersion.toInt()
+        val ndkVersionStr = libs.findVersion("ndk").get().requiredVersion
+        val cmakeVersionStr = libs.findVersion("cmake").get().requiredVersion
+        val javaVersion = JavaVersion.toVersion(libs.findVersion("javaTarget").get().requiredVersion)
+
         with(target) {
             with(pluginManager) {
                 apply("com.android.library")
             }
 
             extensions.configure<LibraryExtension> {
-                compileSdk = Versions.COMPILE_SDK
-                ndkVersion = Versions.NDK
+                compileSdk = compileSdkVersion
+                ndkVersion = ndkVersionStr
 
                 externalNativeBuild {
                     cmake {
-                        version = Versions.CMAKE
+                        version = cmakeVersionStr
                     }
                 }
 
                 defaultConfig {
-                    minSdk = Versions.MIN_SDK
+                    minSdk = minSdkVersion
                     lint {
-                        targetSdk = Versions.TARGET_SDK
+                        targetSdk = targetSdkVersion
                     }
                     testOptions {
-                        targetSdk = Versions.TARGET_SDK
+                        targetSdk = targetSdkVersion
                     }
                     externalNativeBuild {
                         cmake {
@@ -53,8 +64,8 @@ class AndroidLibraryConventionPlugin : Plugin<Project> {
                     }
                 }
                 compileOptions {
-                    sourceCompatibility = Versions.JAVA
-                    targetCompatibility = Versions.JAVA
+                    sourceCompatibility = javaVersion
+                    targetCompatibility = javaVersion
                 }
 
                 // Studio will not automatically pass logcat through ndk-stack, so we need to avoid

build-logic/src/main/java/com/android/ndk/samples/buildlogic/KotlinConventionPlugin.kt

@@ -1,25 +1,23 @@
 package com.android.ndk.samples.buildlogic
 
-import com.android.build.api.dsl.ApplicationExtension
-
+import org.gradle.api.JavaVersion
 import org.gradle.api.Plugin
 import org.gradle.api.Project
-import org.gradle.kotlin.dsl.configure
+import org.gradle.api.artifacts.VersionCatalogsExtension
+import org.gradle.kotlin.dsl.getByType
 import org.gradle.kotlin.dsl.withType
+import org.jetbrains.kotlin.gradle.dsl.JvmTarget
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 
 class KotlinConventionPlugin : Plugin<Project> {
     override fun apply(target: Project) {
-        with(target) {
-            with(pluginManager) {
-                apply("org.jetbrains.kotlin.android")
-            }
+        val libs = target.extensions.getByType<VersionCatalogsExtension>().named("libs")
+        val javaVersion = JavaVersion.toVersion(libs.findVersion("javaTarget").get().requiredVersion)
 
-            extensions.configure<ApplicationExtension> {
-                tasks.withType<KotlinCompile>().configureEach {
-                    kotlinOptions {
-                        jvmTarget = Versions.JAVA.toString()
-                    }
+        with(target) {
+            tasks.withType<KotlinCompile>().configureEach {
+                compilerOptions {
+                    jvmTarget.set(JvmTarget.fromTarget(javaVersion.toString()))
                 }
             }
         }

build.gradle → build.gradle.kts

@@ -2,5 +2,4 @@
 plugins {
     alias(libs.plugins.android.application) apply false
     alias(libs.plugins.android.library) apply false
-    alias(libs.plugins.jetbrainsKotlinAndroid) apply false
 }

camera/basic/build.gradle.kts

@@ -0,0 +1,30 @@
+plugins {
+    id("ndksamples.android.application")
+}
+
+android {
+    namespace = "com.sample.camera.basic"
+    defaultConfig {
+        applicationId = "com.sample.camera.basic"
+        externalNativeBuild {
+            cmake {
+                arguments.add("-DANDROID_STL=c++_static")
+            }
+        }
+    }
+    externalNativeBuild {
+        cmake {
+            path = file("src/main/cpp/CMakeLists.txt")
+        }
+    }
+
+    buildFeatures {
+        prefab = true
+    }
+}
+
+dependencies {
+    implementation(project(":base"))
+    implementation(libs.appcompat)
+    implementation(project(":camera:camera-utils"))
+}